GFRP管以及LRSFRP管约束高强混凝土圆柱的轴压性能

进行了18根GFRP约束高强混凝土圆柱和2根LRSFRP约束高强混凝土圆柱的轴压试验,研究了FRP管材料、直径和壁厚等参数对FRP约束高强混凝土圆柱轴压性能的影响。结果表明,GFRP管约束高强混凝土圆柱的轴压性能存在尺寸效应。即环向约束应力大小相同时,GFRP管约束高强混凝土圆柱的极限承载力和极限应变随着试件尺寸的增大而减小。随着GFRP管壁厚的增大,GFRP管约束高强混凝土圆柱的极限压应力和极限压应变相应提高。LRSFRP管约束高强混凝土圆柱的延性较GFRP管约束高强混凝土圆柱好。最后,研究了现有FRP管约束混凝土的本构模型对GFRP管和LRSFRP管约束高强混凝土圆柱的适用性。研究发现Teng等人的模型对GFRP约束高强混凝土圆柱的适用性较好。而现有主要FRP管约束混凝土的本构模型对LRSFRP管约束高强混凝土圆柱的适用性较差。

Axial load behavior of high-strength concrete cylinders confined by GFRP tubes and LRSFRP tubes

Eighteen GFRP tubes and two LRSFRP tubes confined high-strength concrete cylinders with various sizes were tested under axial compression. The effects of wall thickness, diameter and material of FRP tube on axial load behavior were investigated. Results show that size effect exists in axial load behavior of high-strength concrete cylinder confined by GFRP tubes. Namely, when the hoop confining stresses are the same, the ultimate bearing capacity and ultimate strain of GFRP tube confined high-strength concrete cylinders decreases with the sizes of specimens increasing. Furthermore, when the wall thickness of GFRP tube increases, both the ultimate compressive stress and the compressive strain of GFRP confined high strength concrete cylinders increase. In addition, the ductility of high-strength concrete cylinders confined by LRSFRP tubes is better than that of high-strength concrete cylinders confined by GFRP tubes. Finally, the adaptability of the available constitutive models for high-strength concrete cylinders confined by GFRP tubes and LRSFRP tubes was studied. It is found that the model proposed by Teng has a good adaptability to high-strength concrete cylinders confined by GFRP tubes. However, the available constitutive models have bad adaptability to high-strength concrete cylinders confined by LRSFRP tubes.